U.S. patent number 4,026,744 [Application Number 05/733,610] was granted by the patent office on 1977-05-31 for glass cord adhesives comprising vinyl pyridine terpolymer/lignin sulfonate-resorcinol-formaldehyde reaction product; method of use and composite article.
This patent grant is currently assigned to The General Tire & Rubber Company. Invention is credited to Otto C. Elmer.
United States Patent |
4,026,744 |
Elmer |
May 31, 1977 |
Glass cord adhesives comprising vinyl pyridine terpolymer/lignin
sulfonate-resorcinol-formaldehyde reaction product; method of use
and composite article
Abstract
Rubber compounds are readily bonded to reinforcing elements,
particularly tire cords of glass fibers, using a one-step dip
process in which the dip contains an alkaline aqueous dispersion of
a mixture of a major amount by weight of a rubbery vinyl
pyridine/styrene/butadiene terpolymer and a lignin
sulfonate-resorcinol-formaldehyde reaction product. Good adhesion
of the cords to a rubber compound are obtained with this
process.
Inventors: |
Elmer; Otto C. (Akron, OH) |
Assignee: |
The General Tire & Rubber
Company (Akron, OH)
|
Family
ID: |
27067194 |
Appl.
No.: |
05/733,610 |
Filed: |
October 18, 1976 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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542974 |
Jan 22, 1975 |
|
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|
Current U.S.
Class: |
428/296.4;
156/335; 524/510; 156/307.5; 428/392; 525/138; 428/297.1 |
Current CPC
Class: |
C08J
5/06 (20130101); C08J 2321/00 (20130101); Y10T
428/249937 (20150401); Y10T 428/249939 (20150401); Y10T
428/2964 (20150115) |
Current International
Class: |
C08J
5/04 (20060101); C08J 5/06 (20060101); B29H
005/02 (); C08L 009/08 (); C08L 061/12 (); C08L
097/00 () |
Field of
Search: |
;260/17.5,29.3,42.18,845,846,3 ;428/392,295 ;156/308,335,11A |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Chem. Abs. 68:P88037e; 64:P6866f; 66:P66340e; 71:P71761a;
73:P36119s; P:68311q; and P:78358z; 75:P152920m; 75:P152774s;
Subject Index 1967-1971 p. 175298 (8th Coll. Index)..
|
Primary Examiner: Tillman; Murray
Assistant Examiner: De Benedictis, Sr.; T.
Parent Case Text
This is a division, of application Ser. No. 542,974 filed Jan. 22,
1975.
Claims
What is claimed is:
1. A method for adhering a reinforcing element to a vulcanized
conjugated diene rubber compound which comprises treating said
element with a composition comprising an aqueous alkaline
dispersion of from about 10 to 30% by weight (as dry solids) of a
mixture of 100 parts of a rubbery vinyl pyridine terpolymer
containing about 50 to 95% of a conjugated diolefin, about 5 to 40%
of vinyl pyridine and about 0 to 40% of a styrene; about 1.0 to 30
parts of a lignin sulfonate, resorcinol and formaldehyde reaction
product; and heat treating said element to remove the water and to
heat set the solids from said composition and to deposit on said
element from said composition a total of from about 2 to 30% by
weight (solids), said heat treatment being conducted at
temperatures of from about 300.degree. to 500.degree. F. for from
about 30 to 150 seconds, cooling said treated element, combining
said cooled treated element with an unvulcanized vulcanizable
rubber consisting essentially of conjugated diene as the major
elastomer component, and vulcanizing the same.
2. A method according to claim 1 where said lignin sulfonate is
present at a level of from 2 to 10 parts.
3. A method according to claim 1 where said reinforcing element is
a cord of glass.
4. A bonded composite material comprising a reinforcing element
embedded in a vulcanized rubber, said element containing a total of
from about 2 to 30% by weight (dry) based on the weight of said
uncoated element of an adhesive composition comprised of a deposit
of a heat set mixture containing 100 parts of a rubbery vinyl
pyridine terpolymer, 1 to 30 parts of a lignin sulfonate, and
resorcinol and formaldehyde reaction product, said adhesive
composition forming a bond between said element and said
rubber.
5. A bonded composite material according to claim 4 where said
lignin sulfonate reaction product contains about 2 to 10 parts by
weight of lignin sulfonate, 2 to 10 parts by weight of resorcinol
and 2 to 10 parts by weight of formaldehyde.
6. A bonded composite material according to claim 4 where said
rubbery vinyl pyridine terpolymer is a terpolymer containing from
about 60 to 80% by weight of 1,3-butadiene, from 10 to 30% by
weight of styrene, and from 5 to 30% by weight of 2-vinyl pyridine
where the parts by weight ratio of said rubbery vinyl pyridine
terpolymer to said lignin sulfonate reaction product is from about
100:5 to 100:30.
7. A bonded composite material according to claim 4 where said
element is a cord of glass.
8. A bonded composite material according to claim 5 where said
element is a cord of glass.
Description
BACKGROUND OF THE INVENTION
The present invention relates to compositions and methods of
bonding cord tire reinforcement to the conjugated diene based
rubber of tire carcasses and the improved structures obtained
thereby.
In the manufacture of cord reinforced tires, the cord is sometimes
coated by the cord manufacturer with a material which improves
adhesion of the cord to the rubber body of the tire. Cord free of
adhesion promoter will be referred to as greige or uncoated. After
the cord is received from the manufacturer in the form of a fabric,
the general practice is to prepare the cord by applying a dip
coating of a latex. The dip coating of the cord generally used
contains a vinyl pyridine/styrene/butadiene terpolymer and a
resorcinolformaldehyde (RF) resin. While these RF resins are quite
effective in performing their desired function, the resorcinol
component is expensive and often unobtainable in the quantities
needed.
Materials in addition to RF resins have been used in the prior art
to improve adhesion in special circumstances. For instance, a
number of proprietary formulations of unknown composition are
marketed for this purpose.
SUMMARY OF THE INVENTION
According to the present invention it has been discovered that
reinforcing cords, particularly glass, but also other cords such as
polyester and aramid (also known as Kevlar)*, can be directly
bonded or adhered to cured rubber by first dipping the cords in a
dip containing an aqueous alkaline dispersion of a mixture of a
rubbery vinyl pyridine terpolymer, a resorcinol-formaldehyde-lignin
sulfonate reaction product, drying the same, and combining said
dipped and dried element with a vulcanizable conjugated diene
rubber compound such as a butadiene-styrene rubber compound and
vulcanizing the same.
Reinforcing cords treated in this fashion exhibit high rubber to
cord adhesion values. Also, aged reinforcing cords retain a major
amount of their original rubber to cord adhesion values.
DISCUSSION OF DETAILS AND PREFERRED EMBODIMENTS
In the present application the term "cords" is intended to include
reinforcing elements used in rubber products including fibers,
continuous filaments, staple, tow, yarns, fabric and the like,
particularly cords for use in building the carcasses of tires such
as truck tires.
The reinforcing element or cord comprises a plurality of
substantially continuous fibers or monofilaments.
In the case of glass, the reinforcing element or fibers contain
little or no twist. In other words, twist is not intentionally
applied to the element or fibers; the only twist, if any, in the
element or fibers is that occasioned on passing through the glass
fiber processing apparatus and on packaging or winding up the cord
to form a bobbin or spool. However, in a continuous process, the
elements can proceed directly from the glass processing apparatus,
can be dipped in the aqueous adhesive cord dip, dried, and given a
twist of about 1.5 turns per inch thereafter. The elements then are
woven into tire fabric having about one quite small pick thread or
element, nylon or polyester, which may be a monofilament, per inch
and calendered with a rubber ply or skim stock. The glass fiber
reinforced ply stock is then ready to be used in the manufacture of
a tire or for other purposes.
Glass compositions, polyesters, polyamides and a number of other
materials, useful in making the fibers for the reinforcing element
or glass tire cord are well known to the art. One of the preferred
glasses to use is a glass known as E glass and described in
"Mechanics of Pneumatic Tires," Clark, National Bureau of Standards
Monograph 122, U.S. Dept. of Commerce, issued November 1971, pages
241-243, 290 and 291. The number of filaments or fibers employed in
the fiber reinforcing element or cord can vary considerably
depending on the ultimate use or service requirements. Likewise,
the number of strands of fibers used to make a fiber reinforcing
element or cord can vary widely. In general, the number of
filaments in the fiber reinforcing element or cord for a passenger
car tire can vary from about 500 to 3,000 and the number of strands
in the reinforcing element can vary from 1 to 10, preferably the
number of strands is from 1 to 7 and the total number of filaments
about 2,000. A representative industry glass tire cord known as
G-75 (or G-75, 5/0) has 5 strands each with 408 glass filaments.
Another representative cord known as G-15 has a single strand
containing 2,040 glass filaments. In this connection reference is
made to Wolf, "Rubber Journal," February, 1971, pages 26 and 27 and
U.S. Pat. No. 3,433,689.
Shortly after the glass fibers are formed they are usually sized
(by spraying or dipping and so forth and air drying) with a very
small amount or fractional amount by weight of a material which
acts as a protective coating during processing and handling of the
glass fibers in forming the strands or reinforcing elements and
during packaging. During the subsequent dipping in the aqueous
adhesive tire cord dip, it is believed that the size is not
removed. Materials for use as sizes for glass fibers are well known
to the art. It is preferred to use a silane as a size, especially a
silane which has groups which can bond or coordinate chemically or
physically with at least parts of the surface of the glass of the
glass fiber and with at least one or more of the components of the
glass fiber aqueous adhesive cord dip. A very useful size to employ
on the glass fibers is gamma-aminopropyl triethoxy silane, or
similar aminoalkyl alkoxy silanes, which, when applied to the glass
fibers, hydrolyzes and polymerizes to form a poly(aminosiloxane) in
which a portion of the polymer is attached to the glass and another
portion contains amine groups (having active hydrogen atoms) for
reaction with components of the cord dip such as the RF resin or
the vinyl pyridine copolymer compound. Various glass fiber sizing
compounds and compositions are shown in U.S. Pat. Nos. 3,252,278;
3,287,204 and 3,538,974.
The type of rubber latex used in the tire cord dip bath of this
invention is a latex of a terpolymer of a vinyl pyridine and a
conjugated diolefin having 4 to 6 carbon atoms. The rubber latex is
of the type described in U.S. Pat. No. 2,561,215 and comprises an
aqueous dispersion of a terpolymer of 50 to 95% by weight of a
conjugated diolefin having 4 to 6 carbon atoms, 5 to 40% of a vinyl
pyridine and 0 to 40% of a styrene. Examples of suitable vinyl
pyrdines are 2-vinyl pyridine, 4-vinyl pyridine, 2-methyl-5-vinyl
pyridine, and 5-ethyl-2-vinyl pyridine.
In practicing this invention, it is usually preferred to use a
latex of a terpolymer of from about 60 to 80% by weight of
1,3-butadiene, 10 to 30% by weight of styrene and 10 to 30% by
weight of 2-vinyl pyridine, the percentage based on the weight of
the three recited components. The Mooney viscosity range of the dry
solids is 40 to 120, preferably 40 to 60 ML-4. Other components may
be present but are not used in the calculation. Excellent results
are obtained using a latex of a terpolymer of about 70% of
1,3-butadiene, 15% of styrene and 15% of a 2-vinyl pyridine, by
weight, having a total solids content of around 30 to 50%. The
terpolymer has a 4 minute Mooney viscosity ML-4 of 50 at
212.degree. F. Further disclosures of rubbery vinyl pyridine
terpolymer latices may be found in U.S. Pat. Nos. 2,615,826 and
3,437,122. The terpolymer can be replaced in a minor part with
other elastomeric materials such as styrene-butadiene, carboxylated
styrene-butadiene and other latex forming materials well known in
the cord dip art.
The lignin sulfonates usable in the dip of the present invention
are selected from materials that are known in the art. They are
made, for example, by the reaction of sulfurous acid on lignin.
This reaction results in the introduction of sulfonic acid groups
in the .alpha. or .gamma. position of the phenyl propane unit:
##STR1## This is followed by reaction with a base.
The lignin sulfonates used in the practice of the present invention
are the water soluble salts. Depending upon pH there may also be
some lignin sulfonic acid groups present. The pH range is from 7 to
12.
The lignin sulfonate reaction product of the present invention is
prepared by dissolving of weighted amounts of resorcinol in water
by agitation; addition of measured amount of NaOH solution; slow
addition of lignin sulfonate powder to the agitated solution to
achieve uniform wetting of the dry powder; agitation until powder
dissolves and addition with stirring of measured amount of
formaldehyde solution with agitation for 5 minutes.
The reaction product (including unreacted components, if present)
contains from 22 to 42% preferably from 27 to 37% lignin sulfonate,
from 27 to 47% preferably 32 to 42% resorcinol and from 21 to 41%
preferably 26 to 36% formaldehyde. All percentages are based on dry
solids of the above recited components.
The final dip is prepared by slow addition of the reaction product
to the terpolymer latex. After addition the mixture is aged
preferably at least 16 hours before use as a cord dip. The pH of
the final dip ranges from about 8 to 11 preferably about 9 to
10.
Lignin sulfonates plus water soluble carbohydrates form the solids
of Orzan A, trade name of Crown-Zellerbach lignin sulfonate. The
other Orzan products are manufactured from Orzan A.
The following properties of a few commercial lignin sulfonates are
tabulated. All products are tan, free flowing, water soluble
powders.
______________________________________ Orzan A Orzan S Orzan P
______________________________________ pH of 25% solution 4 7 5
Water content, % 6 5 5 Bulk density, lb/cu ft 31 31 20 Components
Lignin sulfonic acids 57.0 48 51 Reducing sugars* 15.0 12 12 (as
glucose) Ash 1.5 20 5 Primary cation NH.sub.4 + Na+ NH.sub.4 +
Elemental Analysis C 45.6 41.6 H 5.6 5.0 S 6.4 7.0 N 3.7 0.5 Na
0.05 5.9 ______________________________________ *The following
sugars made up the total sugar content: Mannose 48%, Glucose 15%,
Xylose 15%, Galactose 10%, Fructose 72%
The heat reactable resorcinol-formaldehyde-lignin sulfonate
reaction product is preferably made by reacting formaldehyde (or
formaldehyde donor) with resorcinol or similar phenolic compound
and lignin sulfonate in aqueous media using sodium hydroxide and
the like as a catalyst to form water soluble resins containing
hydroxyl and methylol groups.
The ratio of the vinyl pyridine terpolymer (on a dry basis) to the
reaction product of formaldehyde, resorcinol and lignin sulfonate
is from about 100:5 to 100:30 parts by weight, preferably from
about 100:8 to 100:20 parts by weight.
Water is used in the dip in an amount sufficient to provide for the
desired dispersion of the vinyl pyridine latex particles and the
solution or dispersion of the lignin sulfonate reaction product and
for the proper solids content to get the necessary pick-up of
solids on and penetration between the fibers of the polyester
cord.
The dip thus consists essentially of an aqueous dispersion of the
rubbery vinyl pyridine terpolymer latex, the lignin sulfonate
reaction product; the reaction product being present in a total
amount (as dry solids, dispersed or dissolved in the water per
hundred parts of latex solids) of from about 1 to 30 parts by
weight, preferably 8 to 20 parts. The range of reacted and
unreacted lignin sulfonate in the dip is from about 0.3 to 10
parts, preferably 3 to 7 parts, from 0.3 to 10 parts, preferably 3
to 7 parts, of reacted and unreacted formaldehyde are present, from
0.3 to 10 parts preferably 3 to 7 parts, of reacted and unreacted
resorcinol are present, and the terpolymer is present at a level of
100 parts on a dry weight basis (assuming complete reaction).
Sufficient alkaline material is usually present from the lignin
sulfonate reaction product solution to render the dip alkaline or
additional alkaline material such as NaOH can be added to achieve
this purpose. The function of the alkaline material is to prevent
premature coagulation of the rubbery vinyl pyridine terpolymer and
also to catalyze the resorcinol-formaldehyde-lignin sulfonate
reaction.
The concentration of lignin sulfonate reaction product in the
aqueous dispersion is about 0.5 to about 10% and preferably about 2
to about 7%. The concentration of vinyl pyridine terpolymer on a
wet basis is from about 7 to 40% and preferably about 20 to 35%.
The concentration of solids in the aqueous dispersion (or dip) on a
wet basis is 15 to 45, preferably 20 to 40. A high solids results
in coagulation of the latex and a low solids results in a low
D.P.U. and poor performance of the cord.
In order to apply the adhesive dip to the cords in a reliable
manner, the cords are fed through an adhesive dip bath containing
the rubbery vinyl pyridine terpolymer and the lignin sulfonate
reaction product, into a drying oven where they are dried. Also, as
the cords leave the oven they enter a cooling zone where they are
air cooled. In each case the adhesive-coated cords leaving the dip
are dried in the oven at from about 300.degree. to 500.degree. F.
for from about 30 to 150 seconds. The time the cord remains in the
dip is about a second or so or at least for a period of time
sufficient to allow wetting of the cord by the adhesive
mixture.
The adhesive containing reinforcing elements of this invention is
preferably adhered to a vulcanized blend of natural rubber,
polybutadiene rubber, and rubbery butadiene-styrene copolymer by
curing the same in combination together. The adhesive containing
glass reinforcing element can also be adhered to other vulcanized
conjugated diene rubber, by curing or vulcanizing the same in
combination with the rubber. Examples of other conjugated diene
rubbers include: nitrile rubbers, chloroprene rubbers,
polyisoprenes, vinyl pyridine rubbers, acrylic rubbers,
isoprene-acrylonitrile rubbers and the like and mixtures of the
same. These rubbers prior to curing can be mixed with the usual
compounding ingredients including sulfur, stearic acid, zinc oxide,
magnesium oxide, accelerators, antioxidants, antiozonants and other
curatives and the like well known to those skilled in the art for
the particular rubbers being employed. Rubbers when proportions are
referred to, as referred to here and in the claims, refers to the
elastomer component and excludes the above compounding ingredients,
e.g., a reference to a major component of the rubber being a
conjugated diene polymer would refer to a major component of the
elastomeric content of the composition. The rubbers referred to
above are old and well known in the art and will not be described
in detail here.
The major diene component of the rubber used in the practice of the
present invention is a conjugated diene as opposed to a
non-conjugated diene. Preferably the entire elastomeric component
is conjugated diene polymer, free of
ethylene/propylene/non-conjugated diene.
Fibers, yarns, filaments, cords or fabric and the like coated with
the adhesive of the present invention can have from about 3 to 50%
by weight (dry) total solids from the adhesive dip on the cord
based on the weight of the undipped cord (D.P.U.) and can be used
in the manufacture of radial, bias, or belted-bias passenger tires,
truck tires, motorcycle and bicycle tires, off-the-road tires,
airplane tires, transmission belts, V-belts, conveyor belts, hose,
gaskets, rubbers, tarpaulins and the like. The D.P.U. varies as to
substrate as is known in the art. Glass cord, for example, requires
a D.P.U. of 15 to 30% and an organic cord requires 2 to 10%
preferably 3 to 8%.
The following examples will serve to illustrate the invention with
more particularity to those skilled in the art. In these examples
the parts and percentages are parts and percentages by weight
unless otherwise indicated.
The H-adhesion test referred to above measures the static adhesion
of the dried adhesive coated fibers to cured rubber.
In each case the rubber test specimens are made from one of three
standard type rubber compositions using the following three
recipes:
______________________________________ Stock A Parts by Weight
______________________________________ Natural Rubber 50
Butadiene-styrene rubbery copolymer 50 average 23.5% bound styrene,
SBR-1502, emulsion polymerized High abrasion furnace carbon black
20 "Endor", activated zinc salt of 0.5 pentachloro - thiophenol,
peptizing agent, duPont "Circosol" 2XH, napthenic type oil 7.0 Sun
Oil Company Zinc Oxide 3.0 Stearic Acid 1.0 "AgeRite Spar", a
mixture of mono-, di- 1.0 and tri-styrenated phenols, antioxidant,
R. T. Vanderbilt Co., Inc. "Picco 100", alkyl aromatic polyindene
2.0 resin, reinforcing and processing oil, Pennsylvania Industrial
Chemical Corp. Diphenylguanidine 0.5 N-Oxydiethylene benzothiazole-
0.9 2-sulfenamide Sulfur (insoluble) 2.6 Stock B Parts by Weight
______________________________________ Natural rubber 46.64
Butadiene-styrene rubbery copolymer, 38.5 average 23.5% bound
styrene, SBR-1500, emulsion polymerized Polybutadiene, solution
polymerized 15.0 BD, about 93% cis-1,4, Raw Mooney ML-4 at
212.degree. F. about 40-50 Carbon black, fast extrusion furnace
45.0 Hydrated silica, "Hi-Sil" 233, PPG 15.0 Industries, Inc. "BLE"
25 antioxidant, a high temperature 2.0 reaction product of
diphenylamine and acetone, Naugatuck Chemical Division of Uniroyal
Processing oil, a blend of highly 5.0 aromatic petroleum fractions
Zinc oxide 3.0 Stearic acid 1.5 "Cohedur" RL, a 1:1 mixture of
resorcinol 4.7 and "Cohedur" A (the pentamethyl ether of
hexamethylol melamine) which is a colorless, viscous liquid which
liberates formaldehyde on heating. Naftone, Inc.
N-tert-butyl-2-benzothiazole-sulfenamide, 1.2 "Santocure" NS,
Monsanto Chemical Co. Sulfur 3.0 Stock C Parts by Weight
______________________________________ Natural rubber (No. 3 Smoked
Sheet) 36.50 Butadiene-styrene rubbery copolymer, 43.50 average
23.5% bound styrene, emulsion polymerized Polybutadiene (solution
polymerized 20.0 BD, about 93% cis-1,4, Raw Mooney ML-4 at
212.degree. F. about 40-50) Carbon black, fast extrusion furnace
35.0 Carbon black, high abrasion furnace 35.0 (high structure)
Alkyl aromatic polyindene resin, 4.5 reinforcing and processing
aid, Picco 100, Pennsylvania Industrial Chemical Corp. Naphthenic
oil, Circosol type 32.80 2XH, Sun Oil Co. Zinc oxide 3.8 Stearic
acid 1.5 Mixture of mono, di and tristyrenated 1.2 phenols, AgeRite
Spar, R. T. Vanderbilt Co., Inc., antioxidant Benzothiazyl
disulfide, Altax, 1.2 R. T. Vanderbilt Co., Inc., accelerator
Tetramethyl thiuram monosulfide, 0.1 active ingredient, Thionex,
accelerator, E. I. du Pont de Nemours & Co., Inc. Crystex,
about 80% insoluble sulfur and 3.0 20% petroleum oil, Stauffer
Chemical Co. ______________________________________
EXAMPLES I, II AND III
High solids glass cord dips were prepared that contained a molar
ratio of resorcinol to formaldehyde of 1:1.6, 16.0g resin per 100g.
latex solids and 36% total solids content. The dips were prepared
by dissolving weighted amounts of resorcinol in water by agitation;
addition of measured amount of NaOH solution, slow addition of
Orzan powder to the agitated solution to achieve uniform wetting of
the dry powder; agitation until powder dissolved; addition with
stirring of measured amount of formaldehyde solution; agitation for
5 minutes and slow addition of this resin to 244g. of a stirred
latex containing 25g. of a copolymer of 48% styrene and 52%
butadiene and 75g. of a terpolymer of 15% styrene, 70% butadiene
and 15% of 2-vinyl pyridine. The dips are aged at least 16 hours
after formulation before being used to coat cords.
Table I shows results obtained in this series, all dips contained
in addition to the latex 53.73g. H.sub.2 O, 2.00g. 1N NaOH and
13.13g. 37% aqueous formaldehyde. The G-15 glass cord was dipped at
room temperature and cured for 45 seconds in a 425.degree. F.
gradient oven.
TABLE I ______________________________________ DIP I* II III
______________________________________ Resorcinol, g. 6.15 6.15
6.15 Orzan S 5 0 0 Orzan A 0 5 0 Orzan P 0 0 5 Viscosity, cps fresh
17 60 370 1 day old 29.5 41 660 D.P.U. % 19 31.5 20.4 31.2 19.1
33.8 Tensile, psi original 65.7 64.8 69.1 66.8 65.9 69.3 humid
aged, 3 days/ 54.1 45.3 63.2 56.1 64 56.7 175.degree. F. H-adhesion
in Stock A Room Temp. 31.0 29.8 22 14.9 19 22.7 250.degree. F. 21.5
20.6 9.8 7.2 13 13.7 H-adhesion in Stock B Room Temp. 43.0 40.2 40
33.5 39.3 39.3 250.degree. F. 29.4 31.2 25.7 23.6 25.6 27.8
______________________________________ *DIP I corresponds to
Example I, etc.
EXAMPLES IV - VII
Table II gives results obtained with two levels of Orzan S and two
different latex combinations. All dips contain 53.73g. H.sub.2 O,
2.00g. of 1N NaOH and 13.12g. of 37% formaldehyde (aqueous). The
dips were prepared in the same manner as Example I.
TABLE II ______________________________________ DIP IV V VI VII
______________________________________ Resorcinol, g. 11.15 6.15
6.15 6.15 Orzan S 5 10 5 10 Latex A.sup.1 244 244 183 183 Latex
B.sup.2 0 0 61 61 D.P.U. % 21.1 21.2 22.5 25.0 H-Adhesion in Stock
A, lbs. 33.0 26.7 30.1 33.3 Tensile, Original, lbs. 72.2 71.6 66.7
63.2 Humid Aged, 3 days/175.degree. F. 68 66.7 57.3 63.7 D.P.U. %
40 44 44 44 H-Adhesion in Stock A, lbs. 29.4 34.6 29.6 27.0
Tensile, Original, lbs. 67.1 60 64.7 61.2 Humid Aged, 3
days/175.degree. F. 51 60 42.8 46.1
______________________________________ .sup.1 Latex A is a 41%
solids latex of a terpolymer containing 15% styrene, 70% butadiene
and 15% 2-vinyl pyridine. .sup.2 Latex B is a 41% solids latex of a
copolymer containing 52% butadiene and 48% styrene.
EXAMPLE VIII
A formaldehyde pre-reacted lignin sulfonate was prepared by
reacting
______________________________________ a. 50g. Ammonium salt of
lignin sulfonate 100g. H.sub.2 O 27g. CH.sub.2 O (37%) for 24 hours
at 80.degree. C. ______________________________________
A glass dip from the methyloated lignin sulfonate was prepared by
blending
______________________________________ 6.0g. Resorcinol 30.0g.
H.sub.2 O Solution I 2.0g. 1N NaOH with 23.5g. Reaction product of
"a." above Solu- 50.0g. H.sub.2 O tion II
______________________________________
Then 6.64g. of 37% CH.sub.2 O were added, and the resulting
solution slowly added to 244g. of a latex containing 100g. of a
terpolymer containing 70% butadiene, 15% styrene and 15% 2-vinyl
pyridine resulting in a dip containing 32% total solids. The dip
was aged 16 hours and glass cord was dipped at two D.P.U. levels.
The following H-adhesion results were obtained:
______________________________________ H-adhesion, lbs. D.P.U. %
Stock A Stock B ______________________________________ 16.5 30.8
37.0 30.4 33.7 37.4 ______________________________________
EXAMPLES IX AND X
The following dips were prepared by mixing the Penacolite solution
and the NaOH solution, slow addition of the lignin sulfonate to the
agitated solution until the lignin sulfonate dissolves; addition
with stirring of the formaldehyde solution; then slow addition of
the resin formed, to 244g. of a latex containing as the solids
component 100g. of a terpolymer containing 65.5% butadiene, 23.5%
styrene and 11.0% 2-vinyl pyridine. Table III sets forth the
results obtained using the composition set forth to coat glass
cords.
TABLE III
__________________________________________________________________________
DIP IX X
__________________________________________________________________________
Penacolite R2170.sup.1 10.5 10.5 Lignin sulfonate 6.1.sup.2
6.1.sup.3 1N NaOH 4.0 4.0 H.sub.2 O 50.0 50.0 CH.sub.2 O (37%) 9.5
9.5 D.P.U. % 20 32.2 21.3 26.5 Tensile, lbs. 71.3 72.4 72 70.9 Aged
175.degree. F./3 days/H.sub.2 O 62.1 48.4 59.5 54.1 Aged
300.degree. F./24hrs/H.sub.2 O 35.7 36.9 41.7 41.1 Stock A Stock B
Stock A Stock B Stock A Stock B Stock A Stock B
__________________________________________________________________________
H-adhesion 33.6 43.2 31.0 42.4 31.1 40.6 30.6 41.1 Aged 300.degree.
F./24hrs/H.sub.2 O 18.0 30.0 20.0 32.8 17.3 28.0 21.2 33.0 After
dipping, the cords were cured for 45 seconds at 440.degree.
__________________________________________________________________________
F. .sup.1 A 75% solids solution in water of the acid reaction
product of one mole of resorcinol with one-half mole formaldehyde.
.sup.2 Orzan S .sup.3 Orzan LS - Orzan S with carbohydrates
removed.
EXAMPLES XI AND XII
The following dips were prepared in the same manner as in Example
IX and X using 244g. of the same latex.
TABLE IV ______________________________________ DIP XI XII
______________________________________ Penacolite R2170, g. 10.5 --
Resorcinol, g. -- 6.15 Orzan S, g. 6.1 5 1N NaOH 4.0 4.0 CH.sub.2 O
(37%), g. 9.5 13.12 H.sub.2 O 50.0 50.0 D.P.U. % 21.3 32.5 20 30.6
H-Adhesion, Stock A, lbs. Room Temp. 39.1 34.4 31.5 32.1
250.degree. F. 25.1 23.8 21.2 19.7 Aged 300.degree. F/24
hrs/H.sub.2 O 21.6 21.4 19.9 19.1 H-Adhesion, Stock B, lbs. Room
Temp. 44.1 39.0 44.6 44.9 250.degree. F. 27.4 29.8 30.4 29.9 Aged
300.degree. F/24hrs/H.sub.2 O 32.1 33.4 33.9 30.2 Tensile,
Original, lbs. 74.5 73.9 70.1 61.7 Aged 175.degree. F/3
days/H.sub.2 O 67.2 60.3 66.9 61.5 Peel Adhesion, Stock A, ppi Room
Temp. 39.9 38.2 38.0 38.5 250.degree. F. 24.8 21.7 25.2 22.2 Aged
300.degree. F/24hrs 23.3 22.7
______________________________________
EXAMPLE XIII
a. Solution B was prepared by mixing the following components:
______________________________________ Parts
______________________________________ Resorcinol 6.15 Orzan S 5.0
37% Formaldehyde in H.sub.2 O 13.12 1N NaOH (4% NaOH) in H.sub.2 O
2.0 H.sub.2 O 53.73 80.00 (16.0 parts of solids)
______________________________________
A quantity of Solution B containing 16.0 parts of solids was slowly
added to 244 parts vinyl pyridine latex (1). Water was then added
to produce a dip with about 20.0% total solids content. This dip is
called Dip 2.
b. A pre-dip was prepared by mixing together:
______________________________________ Parts
______________________________________ phenol blocked methylene bis
para phenylene diisocyanate 3.6 glycerol epichlorohydrin reaction
product 1.36 gum tragacanth 0.04 water 95.0
______________________________________
Polyester cord 1300/3 was dipped first in the pre-dip, dried, then
dipped in Solution B. The cord was passed then into a hot air oven.
The oven temperature was 430.degree. F., and the time in the oven
was about 45 seconds. After said drying and curing, the adhesive
treated cord was laminated with standard type rubber compounded
Stock C, and molded, and the resulting assembly was cured for 20
minutes at 305.degree. F. After curing, the assembly was removed
from the mold, cooled and tested according to the H-adhesion test
described supra. The H-adhesion of the cord was 62.5 pounds per
linear inch at room temperature and 39.5 at 250.degree. F.
EXAMPLE XIV
An aramid core was dipped in solution B and dried in the same
manner as the polyester cord. The H-adhesion at room temperature in
stock C was 46.3. An aramid is a high molecular weight, aromatic
polyamide. The cord is available from Du Pont.
The high molecular weight aromatic polyamides are obtained by
condensation of metaphenylene diamines with isophthalic acid or
paraphenylene diamines with terephthalic acids or m, p, or
o-benzamides or mixtures of the above isomeric amines with isomeric
acids. It is also possible to make polyamides using the
above-mentioned isomers with substituents on the phenyl groups,
halogen (--Cl), alkyl (CH.sub.3 --), etc., or to use diphenyl acids
with diamines or aromatic diamines and/or diacids in which the
aromatic nuclei are spaced by: ##STR2## Instead of phenylene
groups, the polymers can partly or totally contain heterocyclic
rings.
EXAMPLE XV
Nylon cord was dipped in the lignin sulfonate dip of the present
invention with satisfactory results, though the results were not as
outstanding as those obtained with polyester, polyimide and glass.
The dip is also applicable to rayon, cotton, steel and other
cords.
The H-adhesion test is run using the following procedure:
In every case the glass cords to be treated are placed in parallel
positions in a multiple-strand mold of the type described in the
single-cord H-pull adhesion test designated ASTM D 2138-67, the
mold is filled with unvulcanized rubber of the above-described
compositions, the cords being maintained under a tension of 50
grams each, and the rubber is cured 20 minutes at around
305.degree. F. to the elastic state. Each rubber test specimen is
1/4 inch thick and has a 3/8 inch cord embedment.
After the rubber has been cured, the hot reticulate cured rubber
piece is removed from the mold, cooled, and H-test specimens are
cut from said piece, each specimen consisting of a single cord
encased in rubber and having each end embedded in the center of a
rubber tab or embedment having a length of around one inch or so.
The specimens are then aged at least 16 hours at room temperature.
The force required to separate the cord from the rubber is then
determined at room temperature or 250.degree. F. using an INSTRON
tester provided with specimen grips. The maximum force in pounds
required to separate the cord from the rubber is the H-adhesion
value.
The Chemstrand Strip Adhesion test involves drumwinding dipped cord
at the highest possible end count so as to eliminate all rubber
strike through in the subsequent preparation of the sample. Samples
of the same test stocks as were used in the H-adhesion test are
calendered to 0.015 inch gauge and is sandwiched between two layers
of the drum-wound cord. The construction is reinforced with
calendered nylon square woven fabric to provide stiffness, and the
resultant sample is vulcanized. The adhesion is measured as the
force required to strip the test stock from the cord on a 1-inch
wide sample, pulling parallel to the axial dimension of the cord at
a peel angle of 180.degree..
D.P.U. refers to dip pickup in percent by dry weight and represents
the weight of the coating divided by the bare glass or other cord
weight.
* * * * *